1. Field of the Invention
This invention falls within the medical field of tissue and cell sample analysis.
The invention relates more particularly to the preservation and storage of such samples.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
As part of the medical care of a patient or for research purposes, tissue or cell samples may be taken for histological and/or molecular analysis. For preservation purposes, these specimens are dehydrated and then stored embedded in paraffin in a container commonly known as a “cassette”. After preparing the slices of the specimens needed for histological and/or molecular analysis, the tissue and cell residues embedded in paraffin are retained in order to be able to perform further analyses subsequently (sometimes years later).
Such cassettes generally consist of a box in a standardised rectangular parallelepiped shape, with or without a lid, the bottom of which is of an openwork design with through holes. In addition, one of the side walls, generally the front wall has an area for marking with unique identifying information about the specimen, such as a reference number. Such a wall may be provided inclined, in order to facilitate the reading of said information.
Several examples of such cassettes are described in patents U.S. D448 487 S, U.S. Pat. No. 4,421,246 and GB 2 113 249.
These cassettes and their samples are listed and stored by different establishments, in particular medical laboratories. By law, they must be kept for each individual for a period of at least ten years for private companies, and this can reach several decades for a public establishment or the pharmaceutical industry.
Such a cassette is generally of standardised dimensions, with a height of 41.8 millimeters (mm), a width of 28.5 mm and a height or thickness of 6.5 mm.
Currently, said cassettes are stored and handled manually, by operators who have not necessarily been trained and without any controls. As a result, such manual handling leads to errors and a considerable amount of time wasted in looking for them and in some cases even the loss of certain samples.
In addition, in this context, quantities of existing cassettes are constantly growing: from approximately 200 million a year in the 1990s their number had risen to almost 400 million a year by 2010 and is expected to continue growing to reach 750 million a year by 2030. This being the case, the storage capacities and empirical means currently used are not designed to support the management of the rational and secure storage of such quantities.
Therefore, a computerised automated system of organising cassettes of biological specimens has been designed. Such a system seeks to be able to provide traceability and rational management of cassettes, in large numbers, in particular when they are kept in separate geographical locations.
To do this, such a system provides, first of all, means of storing several cassettes, by positioning them in at least one horizontal storage container in the form of a drawer. The latter contains compartments formed by vertical walls extending across the entire width of the drawer, thereby creating several separate columns. The width of the columns corresponds to that of the cassettes to be inserted in them. In addition, each column is subdivided over its entire length into compartments, separated by lugs formed facing one another and protruding orthogonally relative to each wall, extending towards the inside of said column. In addition, said lugs are spaced according to the thickness of a cassette. Each compartment is then able to hold one cassette.
Thus, the cassettes are positioned within the drawer according to columns and rows. In addition, said cassettes are arranged vertically therein, the side containing the identifying information being turned upwards. Such information will be unique to each cassette. It may be recorded in a management system, to provide traceability as well as cross-referencing with the tissue embedded in each cassette and also the patient's medical record.
Furthermore, this identifying information is presented in the form of an optical code, in particular in the form of a barcode or data matrix code, designed to be read by an optical reader, in particular in the form of a light scanner.
Such a system has the advantage of not involving any ordering at the time of placing said cassettes in such a storage device, as the cassettes can be positioned without any precise order of arrangement when filling the columns and rows. The organisation of this particular form of storage results from the automatic means of reading said information present on each cassette and the computerised referencing of the position of said cassette within the storage means.
This system of storing cassettes in the form of a drawer and of organising said cassettes is described in patent FR 2 985 590, which deals in a general manner only with the principle of storage and detection, without envisaging any specific and optimum detection technique.